Sir Elton John is due to duet with John Mayer, the singer-songwriter who beat him to a Grammy, at his famous Oscar party.
Sir Elton is a tireless fundraiser for Aids causes
The star's Academy Award party is held each year to raise money for the Elton John Aids Foundation.
Mayer, the 25-year-old who won the best pop vocal performance Grammy for Your Body is a Wonderland, will sing with Sir Elton at the end of the event.
About 200 guests will gather for a five-course dinner as they watch the ceremony live on television.
His post-Oscar parties are also legendary and are guaranteed to attract a host of A-list stars making their way around the celebration circuit.
Among the fundraising activities at the dinner will be an Oscar sweepstake, with guests correctly guessing the winners picking up luxury prizes.
Sir Elton will then take to the stage with Mayer, at the event being held at the Marquee club in West Hollywood on 23 March.
Sir Elton said: "I'll be singing with him as well.
"We'll either do Your Body is a Wonderland ... and we'll
probably do one of my songs together, which we haven't
worked out yet."
Last year's Sir Elton party raised nearly $500,000 (£313,429) for his Aids foundation, adding to its total of $45m (£28.8m).
Sir Elton has won an Oscar himself, shared with Sir Tim Rice, for best music for Can You Feel the Love Tonight from The Lion King in 1994.
Pianist Mayer has been making waves touring with Billy Joel in the US.
He is then due to start work writing the music for an animated film called Gnomeo and Juliet.